The situation when the smartphone screen remains active during a telephone conversation is one of the most common and annoying problems of users Android. This is not just visual discomfort: a lit display in close proximity to the face leads to accidental presses, activation of the speakerphone, dropped calls or opening of extraneous applications. In the worst case, if the phone was in a pocket or bag along with the keys, touch input can lead to unpredictable actions and even financial losses.
The main reason for this behavior lies in incorrect operation proximity sensor. This small sensor, usually located on the top of the case next to the earpiece, is supposed to detect the presence of an object (your ear) and send a signal to the system to turn off the backlight. However, software glitches, dirt, protective glass or shell features can disrupt this chain. In this article, we will analyze in detail methods for diagnosing and solving the problem on various device models.
Before moving on to complex settings or resetting data, it is necessary to exclude the most obvious physical factors. Often the problem can be resolved by simply cleaning the top of the screen or checking the accessories. If it's a software issue, we'll need to delve deeper into the engineering menu or developer settings. Let's go through all the stages of restoring the functionality of the sensor one by one.
Physical reasons for blocking the proximity sensor
The first step is to inspect the device visually. The proximity sensor works on the principle of emission and reflection of an infrared beam. Any obstacle in the path of this beam can be perceived by the system as the constant presence of an object, which is why the screen may not turn on at all during a call, or vice versa - not turn off if the sensor is “stuck” in a certain state.
One of the most common reasons is poor-quality or incorrectly glued protective glass. Many accessory manufacturers do not provide a cutout for the sensor, or use glass that is too thick, which scatters the IR beam. The problem can also be caused by a thick case that covers the top frame of the device. Try removing the case and wiping the top of the screen with a soft cloth, paying special attention to the area above the speaker.
If you recently replaced the display module or repaired the phone, the technician may have connected the sensor cable incorrectly or used a non-original spare part. In such cases, the physical location of the sensor may be offset from the factory firmware calibration values. This requires either flashing with the correct drivers or physically re-soldering the component at a service center.
⚠️ Attention: Do not use harsh chemicals or abrasives to clean the sensor area. Alcohol-containing liquids can damage the oleophobic coating or get inside the case through the speaker mesh.
Try to temporarily remove the protective glass and test the call. If the problem disappears, replace the glass with a model with a special cutout for the proximity sensor.
Software calibration and testing of the sensor
If physical obstacles are excluded, the next step will be a software test. The operating system Android has hidden tools for diagnosing equipment. Access to them may differ depending on the manufacturer: Samsung, Xiaomi, Huawei or pure Android use different codes to enter the engineering menu.
For most devices, the universal method is to enter a special USSD command in the "Phone" application. This opens a hidden menu where you can run an automatic test of all sensors. The test will ask you to cover the top of the screen with your hand and see if the sensor value changes. If the value does not respond to your actions, then the problem is hardware or requires deep calibration.
Below is a table with codes for entering the engineering menu on popular brands. Please note that on some new models these codes may be blocked by the telecom operator or manufacturer.
| Smartphone brand | Login command | Section for verification |
|---|---|---|
| Samsung | #0# |
Sensor → Proximity Sensor |
| Xiaomi / Redmi | ##6484## |
Proximity Sensor |
| Huawei / Honor | ##2846579## |
Single Item Test → Proximity |
| Clean Android (Pixel, Motorola) | ##4636## |
Phone Information (test via applications) |
After entering the menu, select the item associated with Proximity Sensor. Cover the top of the phone with your palm. The digital readings on the screen should change (for example, from 5.0 to 0.0) or the green indicator should light up. If there is a reaction, but the screen does not go off in real life, a calibration reset is required. If there is no reaction at all, try rebooting the device and repeating the test.
☑️ Proximity sensor diagnostics
Application settings and system conflicts
Sometimes the sensor itself is working fine, but a third-party application is intercepting control of the screen or blocking it from turning off. Most often, the culprits are various “dialers” (number dialing applications), which users install from Google Play instead of standard ones. Such apps may have their own sensor control settings that conflict with the system.
Go to the settings of the specific dialer application. Find the section responsible for incoming calls or the screen during a call. Try disabling options like “Use proximity sensor” and turning them back on, or completely uninstalling the third-party application and testing it with a standard system dialer. Also, the problem can be caused by applications for recording conversations or caller ID running on top of the screen.
Another important aspect is the power saving mode. In an attempt to save battery power, some shells Android may limit the operation of background processes responsible for polling sensors. Try disabling the power saving mode and check if the problem goes away. Also, make sure that the accessibility settings do not enable features that keep the screen active.
⚠️ Attention: If you are using custom firmware (LineageOS, Pixel Experience, etc.), make sure that the correct driver package (GApps and Firmware) for your model is installed. Version mismatches often break the operation of sensors.
Resetting settings and calibration via Recovery
If simple methods do not help, you can try resetting the sensor settings through a special recovery menu or resetting all phone settings. This action will not delete your personal data (photos, contacts), but will return system settings to factory defaults. Before doing this, be sure to create a backup copy of important information.
On some devices, for example Xiaomi, there is a hidden calibration menu accessible through dialing ##64663## (CIT engineering menu). There you can select the "Proximity Sensor" item and click the "Calibration" button. The phone will ask you to remove your hand from the screen and then close the sensor. After successful calibration, the message “Pass” will appear.
In more complex cases, when the software failure is deeper, a complete data reset (Hard Reset) helps. This is a last resort measure that should only be used if you are sure that the problem is not hardware. To enter Recovery mode, you usually use a combination of the volume and power buttons when the device is turned off. Select item Wipe data/factory reset and confirm the action.
What to do if the reset did not help?
If even after a complete reset and flashing the sensor does not work, the probability of a hardware failure is 99%. This could be oxidation of contacts, loose cable, or failure of the sensor itself. In this case, only a visit to the service center will help.
Solution for devices without a physical sensor
There is a category of smartphones, especially in the budget segment or some models Xiaomi and Honor, where the physical proximity sensor is replaced by a software algorithm. Such devices use a gyroscope and an accelerometer: the phone understands that you have brought it to your ear by changing its position in space. This technology is less accurate and often fails.
For such models, the solution often lies in updating the software. Manufacturers regularly release patches that improve the operating algorithms of the “virtual” sensor. Check for updates in the Settings → About phone → System updatesection. If the update does not help, you can try third-party applications from the store that emulate the sensor using data from other sensors.
However, it is worth remembering that software emulation will never work as perfectly as a physical IR sensor. In such cases, users often get into the habit of manually locking the screen with the power button before starting a call to avoid accidental presses. This is not the most convenient, but a working solution for devices with design features.
On smartphones with a virtual proximity sensor, the accuracy of the response depends on the speed and angle of bringing the phone to the ear. Sudden movements may not be considered by the system as the beginning of a conversation.
When help from a service center is needed
There are situations when no app manipulations produce results. If in the engineering menu the sensor does not respond to the hand, the values do not change, and the calibration gives an error, most likely there is a hardware problem. This may be due to the device being dropped, moisture ingress, or simply a factory defect of the component.
It is also worth contacting specialists if the sensor is unstable: the screen goes out by itself when you just hold the phone in your hand, or does not turn on after the end of the call, requiring a reboot. Replacing the proximity sensor yourself is only possible if you have soldering skills and special equipment, since it is often integrated into the display cable or front panel.
Do not delay repairs if the problem occurs constantly. Keeping the screen on all the time during a call not only wastes the battery, but can also cause the device to overheat in the face area, which is unsafe. In addition, the risk of performing an accidental action (for example, sending a message or transferring money) is too great to ignore the malfunction.
⚠️ Attention: Menu interfaces and codes may vary depending on the version Android and shell of the manufacturer. If the above codes do not work, look for the current combination for your specific model on the official support forum.
Frequently asked questions (FAQ)
Why does the screen go blank when I'm just holding the phone in my hand and not talking?
This is a sign that the sensitivity of the sensor is too high or it is dirty. Try wiping the top of the screen thoroughly. If this does not help, you may need to lower the sensitivity through the engineering menu, if such an option is available for your model.
Is it possible to completely disable the proximity sensor?
With standard means Android this cannot be done, since the function is critical for safety. However, there are applications like "Proximity Sensor Reset" or settings in custom firmware that allow you to ignore sensor readings, but this is not recommended due to the risk of accidental clicks.
Does a magnetic case affect the operation of the sensor?
Yes, some cases with magnetic clasps or metal inserts may interfere with operation sensors including proximity sensor and compass. Try removing the case and checking the phone's operation without it.
Will updating Android help fix the problem?
Very likely. Many updates contain driver bug fixes and improve sensor signal processing algorithms. Always keep the device firmware up to date.
What to do if, after replacing the screen, the sensor stops working?
Most likely, when replacing a non-original display module, in which the sensor is missing or faulty, or the technician forgot to connect the corresponding cable. It is necessary to contact the service to check the quality of installation and compliance of the spare part.